After reading David Rowland's excellent The Stress of Battle:
quantifying human performance in combat, I decided to try an quantify the
relative casualty producing performance on the battlefield of different classes
of weapons. After a great deal of research and data manipulation I came up
with the following figures:

Rifles

MG

Mortars

Artillery

Ratio

1.0

14.9

54.5

42.3

Casualties per "day"

0.5

7.45

27.25

21.15

This shows that the average MG is about fifteen times more
effective than a rifle and a mortar is over fifty times as effective. As Rowland
demonstrated that on average a rifleman does half a casualty a day we can work
out other weapons casualty producing potential

I was particularly taken with the following equation, quoted from the link
above: MG equivalents for casualty causing are: 9 rifles = 1 MG; 1 medium mortar
(81mm) = 3 MG. Or normalised to a rifle;

1 rifle = 1 rifle , 1 MG = 9 rifles and 1 81mm Mortar = 27 rifles

Furthermore there was a a note in the book that artillery fire could be
related to the effectiveness of of the 81mm Mortar by comparing the product of
the sustained Rate of Fire (ROF) and the Mean Area of Effectiveness (MAE) . As
luck would have it I'd compiled a fairly extensive set of ROF and MAE figures
for another project so computing relative artillery firepower would be a few
minutes with a spreadsheet.

When writing the BBWW2B rules I had picked the firepower factors based on
experience of widely reading around the subject and having played an awful lot
of wargames. None the less the factors could best be characterised as being
select by "gut feeling". Obviously it would be useful to come up with better
factors based on research and it looked like Rowland's formula would be just the
trick. A quick look in a few books with TO&Es gave me a selection of battalion
organisations to work with, so I calculated the battalion fire-power using
Rowland's formula.

The good news is that battalions have pretty much the same firepower figures.
On average a battalion inflicts 751 casualties a day, the highest in my chart
was a 1944 German Panzer Grenadier Bataillon at 895 (those extra LMGs make a
difference) and the lowest was the 1944 German Volks Grenadier Bataillon at 637
(the light manning of the battalion makes a difference despite all the heavy
weapons). Note these are the final figures, rather than those I started with but the
pattern was the same. This was pleasing because I could reasonably get away with
using "generic" figures for battalion in BBWW2B and would not have to rate each
one individually.

The bad news is that Rowland's figures seem off for mortars and artillery. Table 1 shows
the relative performances of weapons in inflicting casualties.

Weighting

Rifles

MG

Mortars

Artillery

Dupuy TLI (basic)

1.0

10.0

78.1

780.9

Dupuy TLI (no range)

1.0

10.0

50.0

331.8

Korean War Turks

1301

1.0

12.7

Korean War US

50894

1.0

14.3

65.3

69.1

Korea 7th Cav (intense period)

185.5

1.0

14.3

91.6

10.2

Manoeuvre Control

1.0

5.0

13.5

37.0

Rowland (adjusted)

47

1.0

6.5

69.1

45.2

Rowland (basic)

1.0

9.0

27.0

Vietnam

9207

1.0

11.2

37.4

41.8

Vietnam 2

500

1.0

6.7

14.4

WW2 Bourgainville

1788

1.0

7.2

38.7

49.4

WW2 Burma

369

1.0

34.1

18.4

32.3

Average

1.0

13.4

47.9

41.3

Weighted Average

1.0

13.7

58.7

62.3

Average Coloured

1.0

14.9

54.5

42.3

Supression

1.0

7.5

36.2

43.3

Table 1: Infantry Firepower Normalised to a Rifle

If you look at the "Rowland (basic)" line you can see Rowland's ratios
expressed. As you can see the mortar rating is almost the lowest in the table. When I calculated
the artillery values for my typical battalions the artillery rate was lower
still, much lower than any other rating in the table.

Even a cursory look for "causative agent" for casualties on the internet
indicates that "fragments" (i.e. mortars and artillery) cause 60-70% of battlefield casualties. If you apply
Rowland's figures to my "average" battalion, rifles kill 56% of the casualties, MGs 37%, mortars 22% and artillery 8%. The artillery portion is from a slice of
the regimental guns and (usually) a battery of divisional guns. My first thought
was that by limiting the supporting artillery to a battalion slice I did not
have enough guns represented. However a sensitivity analysis showed I needed to
add over 100 guns to each battalion to get 60% or so casualties.

The next step was to get some detailed causative agent information. Luckily
the US was a keen researcher in this area and has given us some detailed
databases, one for the Bougainville campaign, one for US troops in Burma, a
database of the whole Korean War, database of the 7th Cavalry's engagements
in Korea and two separate studies of Vietnam casualties. Handily these are available on line

The Bougainville and Burma data bases are the detailed and break
out casualties for enemy rifles, MG, mortars and artillery. They also have data
for fratricide casualties (a shocking 18% in Burma), which I subtracted form the
overall casualty tables. Japanese forces on Bougainville had considerable
artillery support, similar to what would be available in NWE. The forces in
Burma had much less mortar and artillery support, plus much of the combat was in
think jungle where it is difficult to see targets to call artillery upon. This
gives a much reduced ratio of artillery and mortar casualties to rifle
casualties. To compensate the proportion of MG casualties is much increased. The
Burma data is quite far removed from figures in more open terrain and certainly
different from the NWE battlefields studied by Rowland.

Causative agent

Total casualties

Dead

Living

Number

Percent

Number

Percent

Number

Percent

Rifle

445

24.9

143

32.1

302

67.9

Machinegun

151

8.4

87

57.6

64

42.4

Artillery

194

10.9

44

22.7

150

77.3

Mortar

693

38.8

82

11.8

611

88.2

Grenade

224

12.5

14

6.2

210

98.3

Mines

34

1.9

13

38.2

21

61.8

Miscellaneous

47

2.6

12

25.5

35

74.5

Total

1,788

100

395

22.1

1,393

77.9

Table 2: Casualties in the Bougainville Campaign

Causative agent

Total casualties

Dead

Living

Number

Percent

Number

Percent

Number

Percent

Machinegun

119

32.3

53

44.5

66

55.5

Rifle

94

25.5

24

25.5

70

74.5

Mortar

62

16.8

10

16.1

52

83.9

Grenade

52

14.1

6

11.5

46

88.5

Artillery

33

8.9

6

18.2

27

81.8

Miscellaneous

9

2.4

2

22.2

7

77.8

Total

369

100

101

27.4

268

72.6

Table 3: Casualties in the Burma Campaign

Korea has two interesting datasets. it has casualties by causative agent for
al US forces in the war and it has a table for the Turkish battalion which
indicates the casualties they believed they inflicted on the NKPA. The latter
only deals with small arms. In the tables below the yellow rows are the
summation of the next (orange) rows

Causative agent

All operations1

Offensive operations

Pursuit operations

Maintain defensive lines

Limited operations from MBP

Defensive operations

Withdrawal operations

Number

Percent

Number

Percent

Number

Percent

Number

Percent

Number

Percent

Number

Percent

Number

Percent

Aviation

5

0.03

0

--

4

0.57

1

0.03

0

--

0

--

0

--

Land transport

27

0.15

6

0.15

3

0.43

4

0.11

4

0.13

8

0.12

2

0.65

Tank

9

0.05

2

0.05

0

--

0

--

4

0.13

1

0.01

2

0.65

Other

18

0.1

4

0.1

3

0.43

4

0.11

0

--

7

0.1

0

--

Bullets, small arms

2,584

13.97

986

25.01

118

16.81

633

17.44

348

11.47

471

6.84

28

9.03

Fragments or explosives

4,883

26.39

1,222

30.98

54

7.7

1,753

48.3

1,341

44.22

508

7.38

5

1.61

Explosive projectile shells

3,859

20.86

958

24.29

47

6.7

1,317

36.28

1,130

37.26

402

5.84

5

1.61

Rockets or aerial bombs

6

0.03

0

--

0

--

5

0.14

0

--

1

0.01

0

--

Land mines

305

1.65

95

2.41

0

--

175

4.82

29

0.96

6

0.09

0

--

Boobytraps

9

0.05

4

0.1

0

--

5

0.14

0

--

0

--

0

--

Grenades

97

0.52

21

0.53

0

--

55

1.52

7

0.23

14

0.2

0

--

Other and unqualified

607

3.28

144

3.65

7

1

196

5.4

175

5.77

85

1.24

0

--

Chemical warfare agents

14

0.08

3

0.08

0

--

5

0.14

4

0.13

2

0.03

0

--

White phosphorus

9

0.05

1

0.03

0

--

5

0.14

1

0.03

2

0.03

0

--

Other

5

0.03

2

0.05

0

--

0

--

3

0.1

0

--

0

--

Accidents in use of own weapons

112

0.61

11

0.28

2

0.28

70

1.93

9

0.3

19

0.28

1

0.32

Other and unknown instruments of war2

10,643

57.53

1,704

43.22

512

72.93

1,146

31.58

1,323

43.62

5,692

82.72

266

85.81

All other causative agents3

230

1.24

11

0.28

9

1.28

17

0.47

4

0.13

181

2.63

8

2.58

Total

18,498

100

3,943

100

702

100

3,629

100

3,033

100

6,881

100

310

100

Table 3: Percent distribution of US KIA by
causative agents in Korea

Causative agent

All operations1

Offensive operations

Pursuit operations

Maintain defensive lines

Limited operations from MBP

Defensive operations

Withdrawal operations

Number

Percent

Number

Percent

Number

Percent

Number

Percent

Number

Percent

Number

Percent

Number

Percent

Aviation

96

0.13

55

0.28

33

0.02

3

0.02

0

--

5

0.03

0

--

Land transport

454

0.63

69

0.35

64

2.43

28

0.16

19

0.15

218

1.18

56

4.38

Tank

123

0.17

20

0.1

22

0.83

16

0.19

11

0.09

38

0.21

16

1.25

Other

331

0.46

49

0.25

42

1.6

12

0.07

8

0.06

180

0.97

40

3.13

Bullets, small arms

19,833

27.42

6,764

34.66

1,139

43.32

2,658

15.15

2,018

15.65

6,670

36.1

584

45.62

Fragments or explosives

46,781

64.66

11,337

58.1

1,089

41.42

13,610

77.55

10,211

79.19

10,086

54.6

448

35.01

Explosive projectile shells

36,379

50.29

8,852

45.36

781

29.71

9,902

56.42

8,080

62.66

8,446

45.72

318

24.84

Rockets or aerial bombs

45

0.06

5

0.03

5

0.19

23

0.13

1

0.01

10

0.05

1

0.08

Land mines

2,401

3.32

599

3.07

74

2.81

1,312

7.48

272

2.11

134

0.73

10

0.78

Boobytraps

261

0.36

37

0.19

2

0.08

173

0.99

36

0.28

11

0.06

2

0.16

Grenades

6,557

9.06

1,548

7.93

161

6.12

1,961

11.17

1,655

12.83

1,144

6.19

88

6.88

Other and unqualified

1,138

1.57

296

1.52

66

2.51

239

1.36

167

1.3

341

1.85

29

2.27

Chemical warfare agents

344

0.48

90

0.47

11

0.42

95

0.54

66

0.51

77

0.41

5

0.39

White phosphorus

303

0.42

85

0.44

10

0.38

79

0.45

60

0.46

65

0.35

4

0.31

Other

41

0.06

5

0.03

1

0.04

16

0.09

6

0.05

12

0.06

1

0.08

Accidents in use of own weapons

1,377

1.9

313

1.6

90

3.42

502

2.86

119

0.92

286

1.55

67

5.23

Other and unknown instruments of war2

1,262

1.74

297

1.52

58

2.21

280

1.6

209

1.62

388

2.1

30

2.34

All other causative agents3

2,196

3.04

590

3.02

145

5.52

373

2.12

253

1.96

745

4.03

90

7.03

Total

72,343

100

19,515

100

2,629

100

17,549

100

12,895

100

18,475

100

1,280

100

Table 4: Percent distribution of US WIA by
causative agents in Korea

Weapon

Enemy killed or wounded

Turkish soldiers involved

M1 rifle

268

65

Carbine

5

2

Pistol

4

2

Machinegun

838

16

Submachinegun

45

6

Browning automatic rifle

6

1

Hand grenade

100

17

Bazooka

6

3

Bayonet

22

9

Knife

1

1

Strangled

3

1

Burned

3

1

Total

1,301

124

Table 5: NKPA casualties inflicted by Turkish Soldiers in
Korea

Table 6: US casualties in Vietnam (Vietnam 1 in Table 1)

Table 7: US casualties in Vietnam (Vietnam 2 in Table 1)

To find the relative effectiveness of weapons in these cases I needed to get
an enemy TO&E. For the Bougainville campaign the intelligence summaries of the
3rd Marine Division are available on line:
www.dtic.mil/dtic/tr/fulltext/u2/a639068.pdfwhich gives an accurate
enemy OB. For the Burma campaign I
assumed the opposition had the same mix of weapons as a supported Japanese
Infantry Battalion, the organisation of which came from Leland Ness's excellent
Rikugun Vol 1. The 7th Cavalry report has a very detailed account of the North
Korean opposition. I used the proportions from that study to apply to the
overall Korean data as it was clear using the full official NKPA TO&E gave
highly suspect results. The Vietnam data assumes the opposition is an NVA
regiment.

To generate the numbers in table 1, I divided the total casualties per weapon
type by the numbers of such weapons in a battalion or division as appropriate. I
then normalised the data so a rifle was shown as a factor of 1, and all other
weapons were shown in proportion to a rifle.

The coloured cells indicate the places where the data was originally
presented broken down into rifles, MGs, mortars and artillery. The non-coloured
cells have been calculated by making assumptions that the data is similar to
another data set.

For the overall Korean data I took only the offensive and defensive
engagements, as in gaming these are the scenarios most likely to be fought out.
For the 7th Cavalry data I took the data from what the author of the report
calls the "intense period". Static warfare gives much higher proportional
artillery and mortar casualties and would distort the figures for a "typical"
wargames scenario.

Despite taking the intense period for the 7th Cavalry data the artillery
still looks low compared to other data sets, even the Burma figures. Thus I
examined the war diaries contained in the report and calculated that the
artillery only fired 76% of the time compared to the mortars. I adjusted the
artillery firepower score to reflect this. Even so the artillery factor is by
far the lowest of any data set, for which I conclude the North Korean Artillery
was not well handled in this battle. This is backed up by other ORO reports on
the Korean War. The statistics for the overall war are much
more in line with other data sets, though this will have figures for many
static periods which will inflate the artillery casualty rate compared to sets
that only deal with battle data.

The astute reader will note that the Korean War data only has a line for
"bullets, small arms", and we need it broken down into Rifles and MGs. I assumed
that the ratio of casualties would be the same as for the 7th Cavalry data set.
As both sets use the same TO&E data for the opposition the relative values are
the same in table 1.

Both sets of Vietnam data have a similar problem, so we need to unpick the
rifle and MG casualties. We have four data points:

The ratio from the 7th Cavalry study which shows 70.1% of casualties
coming from rifles

An entry from Personnel Attrition Rates in Historical Land Combat
Operations: Losses of Divisions and Lower level Combat Forces:
http://www.dtic.mil/get-tr-doc/pdf?AD=ADA325455which says MGs and
rifles roughly contribute 50% of small arms casualties each

The Bourgainville data that shows 74% of casualties coming from rifles

The Burma data that shows 44% of casualties coming from rifles

The average figure is 59.5%, so this was used for the Vietnam calculations.

The TLI is an attempt to classify the lethality of weapons based on their
physical characteristics, such as rate of fire. It is interesting that when
normalised to a factor of 1 for a rifle it gives 10 for an MG which is in close
accordance with Rowland's figure (see table 1). The mortar and artillery scores
are very high compared to others. The TLI has a range factor. I reasoned that if
a weapon was causing casualties it must already be in range. So I re-ran the
figures neglecting the range factor. This brought the mortar into line but the
artillery factor it was still considerably higher than any other data. My
conclusion is the TLI model will probably produce disproportionately high
artillery casualties.

FM105-5 is a manual for running field manoeuvres. It has a section that has
guidelines for umpires so they can resolve combats. This gives the numbers shown
in table 1. It seems to overstate the power of the rifle thus understate the
power of other weapons, though all figures are in the same ballpark as other
data.

Lastly I looked for a way to make Rowland's figures fit actual casualty data
more closely. The mortar data for Rowland is based on the product of the Mean
Area of Effectiveness (MAE) of the weapon and its sustained Rate of Fire (ROF).
Luckily I had a database of MAEs from a previous project. One issue is that MAE
is hugely dependant on type of target, the ground the target is on and the
arrival angle of the shell. Rowland is coy about saying which criteria he used
but I suspect that its for troops standing in the open in open ground. Those
criteria emphasise the effectiveness of mortar bombs over artillery. As one of
the issues with Rowland's data is that artillery produces insufficient
casualties compare to mortars I changed the MAEs to those for men lying prone.
This reduced the artillery MAE by 40% but the mortars by 60%. This marginally
improved the artillery numbers but not enough. Next I removed the ROF factor.
Mortars generally have a higher ROF than artillery, so be removing the ROF this
again boosted the artillery compared to the mortars. Removing the ROF factor is
valid as its the number of missions that can be fired in a given time not how
fast the shells for those missions arrive that is key. This finally put mortar
and artillery fire on a par effectiveness wise. However the casualty ratios were
still off compared to other data sets. I realised that Rowland's data was only
for defences. Data from Korea shows that the effect of different types of
weapons changes depending whether they are used in attack or defence. Artillery
and mortars cause more casualties, proportionally, in defence that rifles and
MGs. By finding these ratios and applying to the modified Rowland data, we get
the "Rowland (adjusted)" entry in table 1. These factors are more in line with
historical totals though the MG figure is fairly low.

So far we have only looked at the physical effects of weapons on soldiers.
However much of weapons' effect is psychological. A great deal of research has
been done on the suppressive effect of weapons, for example:
http://handle.dtic.mil/100.2/ADA081134. In the same way as we can
normalise the destructive effect of a weapon to the destructive effect of a
rifle we can do the same with the suppressive effect. This is reported on the
suppression line of table 1. Its interesting that the suppressive effects of
weapons are very much in line with the destructive effects. Form a game
designer's point of view it means an integrated results table, like that in BBB,
that includes both suppression and destruction is a reasonable way to model both
effects. As an aside I am starting to believe that most peace time studies
grossly under-rate the suppressive effect of fire, but that's a subject for
another essay.

Averages

We have multiple data points which we need to distil down to a representative
average. In Table 1 there are three averages. None of them use the data on the
grey lines. The line that says average is an average of al the non-grey cells.
The weighted average gives more weight to the larger databases and the average
(coloured) only uses only the coloured data and is not weighted.

The weighted average is not particularly useful as its dominated by the Korea
data. The Korea data has long periods of static warfare which tends to show a
much higher proportion of artillery casualties, so it's not representative of
high intensity conflict. It also seem spurious to emphasise the Korean
experience over, for example, the WW2 data.

The average (coloured) I consider the "best" average as its not affected by
manipulation of data to break down small arms and fragmentation data. However
its not very far from the overall average which seems to confirm my data
manipulation as reasonably valid.

The 7th Cavalry artillery figure is so low and such an outlier that I removed
it from the coloured average. For reading other ORO reports on the conflict its
clear that North Korean artillery was poorly handled and fired infrequently,
thus is not representative of the normal destructive effect of shells. However,
it is a clear indication of the effect of doctrine on effectiveness.

Firepower

The following table shows the relative effects of weapons in
causing infantry casualties.

Rifles

MG

Mortars

Artillery

Ratio

1.0

14.9

54.5

42.3

Casualties per "day"

0.5

7.45

27.25

21.15

This is saying that the average MG is nearly 15 times as effective as a
rifle, and that a mortar is fifty times as effective. If we accept Rowland's
original thesis that rifles cause half a casualty a day we can derive
proportional figures for other arms. Of course most units are not in combat
continuously for 24hrs so just dividing the daily rate by 24 will not give a
realistic hourly rate.

Further Questions

Are all rifles created equal? Rowland's data was derived from battles with
bolt action rifles. He had no problem comparing his results with those from
exercises using semi-automatic rifles. However the Vietnam data is for US forces
facing enemies armed with the fully automatic AK-47. Does it make a difference?

Update 17/2/18: The author has done some research on this and the
short answer is that it doesn't make any difference. See the Rules of Infantry Combat

What is a realistic hourly rate? Which is another way of saying how long on
average are soldier engaged in intense combat for? This is vital if ewe are to
use the figures in games development.

All MGs are most certainly not created equal. Can we work out factors for
automatic rifles, LMGs and MMGs? The same for mortars and artillery?

What about other weapons, bayonets, RPGs and Grenades?

What about tanks and armour casualties?

Do the ratios hold for the horse and musket period?

Update 17/2/18: The author has done some research on this. It seems an
artillery piece is worth at most 75 muskets, though this is sensitive to the
level of artillery casualties. 75 casualties only holds if you believe that 20%
of casualties are caused by artillery fire. Many observers hold the percentage
is 10%, so that would make a an artillery piece worth 36 muskets. See The
Tactics and Experience of Battle in the Age of Napoleon by Rory Muir for a
discussion of this.